Food deserts may not be key in what people eat, study says

There's no strong evidence of an association between living within… (Mel Melcon / Los Angeles )

There’s no strong evidence of an association between living within walking distance of places to buy food and being overweight or not, researchers said after interviewing nearly 100,000 Californians.

Given the attention to the idea of food deserts – areas with limited access to healthful food – and their effect on people’s health, the researchers wanted to find how much it mattered to have stores and restaurants within walking distance, which they defined as a mile from home.

But the number of fast-food outlets within three miles of home was associated with eating more fast food, fried potatoes and caloric soft drinks, and with less frequent consumption of produce, the researchers said. And they found that the number of large supermarkets within 1.5 miles and three miles of home was associated with drinking fewer caloric soft drinks.

They said “shopping patterns are weakly related, if at all, to neighborhoods in the United States because of access to motorized transportation.”

The researchers, who reported their findings in last week's journal Preventing Chronic Disease, looked at the habits of 97,678 adults in the California Healthy Interview Survey, and their weight, body mass index, and other indicators such as income.

They overlayed a map to determine the number of fast-food places, full-service restaurants and various kinds of food stores within five ranges, from half a mile to three miles from home.

“Evidence is more tentative than often presented in the news media and in policy arguments” linking obesity with the food environment, the researchers said. That is, the idea that people who live close to lots of fast-food outlets and far from big, well-stocked supermarkets are more likely to be overweight or obese, or to show other health results of poor eating habits.

“The evidence is not clear on whether promoting or discouraging a particular type of food outlet is an effective approach to promoting healthful dietary behavior and weight status,” the researchers said. Los Angeles has tried legislating the types of food outlets in South L.A. to help bring down obesity rates.

The researchers used telephone surveys and respondents reported their intake of various kinds of food, as well as their height and weight. That is a weakness of the research, they said.

Some of the results: Fifty-seven percent of the respondents were overweight or obese; low-income people were surrounded by more food outlets of all types than wealthy people.